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Several questions to dinosaurs fans and experts; I need your help! :)
Topic Started: Sep 20 2015, 05:09 PM (944 Views)
rocking1805
Unicellular Organism
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Hello, everybody! My name is Dmitrii and I have some questions for you. Please, be condescending since English is not my native language :) My friends and me are thinking about a small media project devoted to dinosaurs - a book, a card game, and maybe also a small iOS/Android app. And despite we all are dinosaurs fans we are still amateurs and know not that much except the names of the dinosaurs. That is why I would be very grateful if you could clear up the air and answer several questions or to provide links leading to the answers :) Thank you in advance! Let's go:

1. Are there any other hypotheses of Ceratosaurus extinction except lost competition to Allosaurids?

2. Why could Torvosaurus get extinct? Same reason - it appeared to lose competition to Allosaurus and its family?

3. Is it at least theorerically possible that European ceratosaurus and torvosaurus could survave to middle or late cretacious but we simply
haven't find any fossiles? Or is it obvious that both species got extinct in late Jurassic/early Cretaceous?

4. Do you think that male Baryonix could take part in bringing up and raising its cubs? Or did such dinosaurs probably simply leave the offspring alone and cared only of themselves? I know that the question sounds weird, but maybe someone could draw a parallel between baryonix and crocodiles, for instance.

5. What sounds could dinosaurs make? I.e T-Rex hardly roared like it does in movies, right :) If they were closer to birds, then they were probably able to make some noise, but mostly carnivores, right? Sauropods and ceratopsids probably didn't have a voice, did they?

6. How did dinosaurs sleep? For instance, could small species like, let's say, Scipionyx and Hypsilophodon, sleep on trees? Could sauropods sleep in shallow water? Baryonix could probably sleep in water, didn't it?

7. What lizards could scypionix hunt for? Or maybe someone could guide me which scientific researches I should delve into?

8. Is there any information about insects inhabited Europe in Late Cretaceous?

9. Could anyone share an information where I can read more about the plants and simply the environment of the Cretaceous period? I'm sorry for a weird question again, but I'm really a bit lost in all tons of the information :) Maybe you can recommend some particular literature or researches.

Have a great day everyone!
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Jinfengopteryx
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Aspiring paleontologist, science enthusiast and armchair speculative fiction/evolution writer
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1-2. Species/Genera come and go. In these two cases, competition very likely played a role, along with a changing environment. There was a minor extinction event near the end of the Jurassic:
http://workspace.imperial.ac.uk/earthscienceandengineering/Public/PhDProjects/Imperial%20PhD%20project%20outline%20-%20J-K%20extinction.pdf
3. Theoretically, it is. There are examples of dinosaur groups that survived longer than previously thought.
4. Given that nearly all extant archosaurs (crocodiles and birds) care for their offspring, assuming that the same held true for dinosaurs like Baryonyx is not weird at all.
5. Vocal cords consist of soft tissue and are thus usually not preserved in the fossil record, the exact sounds remain guesswork. T. rex likely would've only roared if it intended to scare off opponents, not during a hunt. Birds and crocodiles are both capable of making sounds, so I guess sauropods and ceratopsids would've been able to make some sounds, too.
6. It is at least known for the dinosaur Mei that it slept in a very bird-like manner (head below the fore limb). About the sleep of other animals, little is known. It is for example currently not known if large dinosaurs were dozing while standing or actually lying on the ground.
7. The diet of Scipionyx is quite well understood:
http://www.researchgate.net/publication/231347243_Scipionyx_samniticus_(TheropodaCompsognathidae)_from_the_Lower_Cretaceous_of_Italy._Osteology_ontogenetic_assessment_phylogeny_soft_tissue_anatomy_taphonomy_and_palaeobiology
Unfortunately, the paper was not able to identify exact species. Maybe the text is still interesting for you, but there is little detail on the genus/species of lizard eaten:

This is a remarkable insight, impossible to determine in almost any other fossil specimen. In fact, today we know that Scipionyx had fed on at least five different prey. First, one or more teleoste- an fish, that we estimate to be 4-5 cm long from the size (0.9 mm) of the scales found. A second, certainly distinct meal, was a smaller-sized vertebrate that, given the diam- eters of the vertebrae (not exceeding 0.5 mm) clustered in the jejunum, we presume to be a clupeomorph-like prey of no more than 2-3 cm in length, after comparison with the Clupavus sp. fossilised near Scipionyx (Fig. 8) and taking into account a vertebral count of 40-50 elements in similar teleosteans (Murray et al., 2005). A third prey of Scipionyx was a lepidosaurian reptile covered with sq- uamae that, based on their size (0.4-0.7 mm in diameter), suggest an animal no more than 10-12 cm long (Dal Sasso & Maganuco, pers. obs., 2010 on MSNM extant reptiles). Fourth came the posterior leg and part of the vertebral col- umn of another reptile, possibly a lizard. Based on Hoff- stetter & Gasc (1969), a vertebral length of 2.4 mm and an ankle diameter of 3 mm are indicative of a total body length of 15-40 cm, a size half that of Scipionyx and that, in all likelihood, would have prevented the Italian comp- sognathid from swallowing this prey whole. In addition, hunting a prey half its own size would have been a chal- lenge too hard to face alone and, therefore, such a meal is either indicative of parental feeding or of a scavenging activity. Fifth and last prey items were smaller vertebrates of uncertain affinities.

8-9. The Scipionyx paper is very elaborate on the world Scipionyx lived in.
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SpinoInWonderland
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rocking1805
Sep 20 2015, 05:09 PM
Hello, everybody! My name is Dmitrii and I have some questions for you. Please, be condescending since English is not my native language :) My friends and me are thinking about a small media project devoted to dinosaurs - a book, a card game, and maybe also a small iOS/Android app. And despite we all are dinosaurs fans we are still amateurs and know not that much except the names of the dinosaurs. That is why I would be very grateful if you could clear up the air and answer several questions or to provide links leading to the answers :) Thank you in advance! Let's go:

1. Are there any other hypotheses of Ceratosaurus extinction except lost competition to Allosaurids?

2. Why could Torvosaurus get extinct? Same reason - it appeared to lose competition to Allosaurus and its family?

3. Is it at least theorerically possible that European ceratosaurus and torvosaurus could survave to middle or late cretacious but we simply
haven't find any fossiles? Or is it obvious that both species got extinct in late Jurassic/early Cretaceous?

4. Do you think that male Baryonix could take part in bringing up and raising its cubs? Or did such dinosaurs probably simply leave the offspring alone and cared only of themselves? I know that the question sounds weird, but maybe someone could draw a parallel between baryonix and crocodiles, for instance.

5. What sounds could dinosaurs make? I.e T-Rex hardly roared like it does in movies, right :) If they were closer to birds, then they were probably able to make some noise, but mostly carnivores, right? Sauropods and ceratopsids probably didn't have a voice, did they?

6. How did dinosaurs sleep? For instance, could small species like, let's say, Scipionyx and Hypsilophodon, sleep on trees? Could sauropods sleep in shallow water? Baryonix could probably sleep in water, didn't it?

7. What lizards could scypionix hunt for? Or maybe someone could guide me which scientific researches I should delve into?

8. Is there any information about insects inhabited Europe in Late Cretaceous?

9. Could anyone share an information where I can read more about the plants and simply the environment of the Cretaceous period? I'm sorry for a weird question again, but I'm really a bit lost in all tons of the information :) Maybe you can recommend some particular literature or researches.

Have a great day everyone!
Here's what I can answer:

1. There was never a hypothesis about Ceratosaurus' extinction. It likely occupied a different niche and wouldn't have directly competed with Allosaurus.

2. Same as above

3. Very very very very very very very very very very very very very very very unlikely. If they survived that long, they would have at least been found once in European Mid-Late Cretaceous formations.

4. Unknown at the moment

5. Dinosaurs likely had a diverse range of vocalizations. Both carnivores and herbivores alike - diet has absolutely nothing to do with vocalization. In fact, the herbivores would likely have been noisier, as carnivores usually stay silent while staking prey.

7. Chometokadmon and probably some other small lizards.
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Thalassophoneus
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I will anser only to question 5.

Birds also show a huge variety of vocalisations. Cassowary's for example produce a deep humming sound. King-of-Saxony birds produce a really bizzare sound.
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rocking1805
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Thank you, guys! Really helpful and informative, exactly what I needed!
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Fist of the North Shrimp
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3: It has been proposed that Ceratosaurus is a "basal Abelisauroid" by multiple parties, though no paper as been published yet.
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theropod
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"1. Are there any other hypotheses of Ceratosaurus extinction except lost competition to Allosaurids?"
None that I’m aware of (though I’m not aware of that being an official hypothesis either. Just because one animal is much more common than another animal, it didn’t automatically drive it to extinction. And do note that neither Ceratosaurus nor Allosaurus seems to have made it past the Jurassic/Cretaceous boundary.

"2. Why could Torvosaurus get extinct? Same reason - it appeared to lose competition to Allosaurus and its family?"
Same here. Also I think the question is perhaps a bit mislead. You could basically ask that for every genus that went extinct, i.e. a countless number. The vast majority of genera go extinct, and no genus lasts forever. It’s nothing unusual.

"3. Is it at least theorerically possible that European ceratosaurus and torvosaurus could survave to middle or late cretacious but we simply
haven't find any fossiles? Or is it obvious that both species got extinct in late Jurassic/early Cretaceous?"
Theoretically possible, but extremely unlikely. You are talking about two genera surviving for more than 50ma. Also there are early and late Cretaceous fossil sites in Europe where I would have expected the fossil record to include them, or at least closely resemble that from the Upper Jurassic, if the ecosystem really changed so little that these taxa survived unchanged.

"5. What sounds could dinosaurs make? I.e T-Rex hardly roared like it does in movies, right :) If they were closer to birds, then they were probably able to make some noise, but mostly carnivores, right? Sauropods and ceratopsids probably didn't have a voice, did they?"
Extant crocodylians tend to rely on low-frequency sounds, and I seem to recall that large theropods were proposed to hear best in those low frequencies too, so they might have been similar to crocodiles in that they produced very low-pitched sounds. In most dinosaurs of course, we have basically no clue what kind of sounds they may have made, but most tetrapods are capable of some sort of vocalization. So I would assume that most dinosaurs weren’t mute either, but there’s a diverse array of possibilities, and only in very few cases do we have clues as to what they may have sounded like.

"6. How did dinosaurs sleep? For instance, could small species like, let's say, Scipionyx and Hypsilophodon, sleep on trees? Could sauropods sleep in shallow water? Baryonix could probably sleep in water, didn't it?"
Probably not, it’s difficult to sleep in water without drowning. For an animal like Baryonyx, which would have had no problem to do so, sleeping on land would be far more convenient.
Perhaps sauropods could theoretically sleep in shallow water (provided they can move there without getting stuck) but I’ve got no idea why they should do such a thing.
Scipionyx and hypsilophodon don’t seem to have any arboreal adaptions, so they probably aren’t your best candidates for sleeping in trees. Not saying that it is impossible, but such a behaviour is more likely in a dinosaur that was actually arboreal (e.g. Microraptor, Scansoriopterygidae etc.).
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DinosaurFan95
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rocking1805
Sep 20 2015, 05:09 PM
Hello, everybody! My name is Dmitrii and I have some questions for you. Please, be condescending since English is not my native language :) My friends and me are thinking about a small media project devoted to dinosaurs - a book, a card game, and maybe also a small iOS/Android app. And despite we all are dinosaurs fans we are still amateurs and know not that much except the names of the dinosaurs. That is why I would be very grateful if you could clear up the air and answer several questions or to provide links leading to the answers :) Thank you in advance! Let's go:

1. Are there any other hypotheses of Ceratosaurus extinction except lost competition to Allosaurids?

2. Why could Torvosaurus get extinct? Same reason - it appeared to lose competition to Allosaurus and its family?

3. Is it at least theorerically possible that European ceratosaurus and torvosaurus could survave to middle or late cretacious but we simply
haven't find any fossiles? Or is it obvious that both species got extinct in late Jurassic/early Cretaceous?

4. Do you think that male Baryonix could take part in bringing up and raising its cubs? Or did such dinosaurs probably simply leave the offspring alone and cared only of themselves? I know that the question sounds weird, but maybe someone could draw a parallel between baryonix and crocodiles, for instance.

5. What sounds could dinosaurs make? I.e T-Rex hardly roared like it does in movies, right :) If they were closer to birds, then they were probably able to make some noise, but mostly carnivores, right? Sauropods and ceratopsids probably didn't have a voice, did they?

6. How did dinosaurs sleep? For instance, could small species like, let's say, Scipionyx and Hypsilophodon, sleep on trees? Could sauropods sleep in shallow water? Baryonix could probably sleep in water, didn't it?

7. What lizards could scypionix hunt for? Or maybe someone could guide me which scientific researches I should delve into?

8. Is there any information about insects inhabited Europe in Late Cretaceous?

9. Could anyone share an information where I can read more about the plants and simply the environment of the Cretaceous period? I'm sorry for a weird question again, but I'm really a bit lost in all tons of the information :) Maybe you can recommend some particular literature or researches.

Have a great day everyone!
1. Direct competition with Allosaurids probably did not play a major factor in the downfall of Ceratosaurus, assuming there is an abundance of prey species, two carnivores can live side-by-side, by going after different species.

2. Torvosaurus does not appear to have been all that common to begin with (or was not commonly preserved), it may simply have been a rare animal that died out due to a smaller gene pool.

3. It IS possible for a species to have survived beyond what the fossil record shows (Coelocanths, for example), but it's rather unlikely that European species of Torvosaurus or Ceratosaurus to have made it to the Late Cretaceous.

4. First off, a better term would be "chicks" or "hatchlings", rather than "cubs". Second off, parental care amongst Theropods (especially male Theropods) was most likely limited to bringing back food to the chicks, anything else was probably the females job.

5. There's nothing to say it didn't. ;) As for ceratopsians and Sauropods, grunts and rumblings were probably the most common sounds. Baby Theropods could possibly have made peeping sounds like newborn alligators do, while Lambiosaurs are almost universally agreed to have honked. Remember that modern avian sounds arn't just chirps.

6. Same way we do, by closing their eyes and slowing down brain function. Lol. But seriously, sauropods possibly slept standing up, remember that sauropods don't have sternums, if they were to lay on their chests, they would have risked damage to their organs. Hypsilophodon, in the trees...why does it feel like I've heard that before?

7. Whatever lizards were around when it was hungry.

8. I'm sure a dig into the wonderful world of the Internet will find you an answer, but I won't be much help to you here.

9. See above.
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SpinoInWonderland
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Allosaurusatrox
Sep 25 2015, 01:22 AM
remember that sauropods don't have sternums, if they were to lay on their chests, they would have risked damage to their organs
WHAT.

The sternums of sauropods have been recovered and are pretty well-known.
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DinosaurFan95
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Where? Would you be kind enough to show me this sauro-sternum?
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Jinfengopteryx
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Here you have some examples:
Posted Image
http://onlinelibrary.wiley.com/store/10.1002/ar.20405/asset/20405_ftp.pdf?v=1&t=if3zpmee&s=f8ce512ec4716f584180c522a7377fc85594538b
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DinosaurFan95
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Yes, while those are indeed sternums, they are not positioned correctly to provide protection to the sauropods inner organs if it were to lay down. In other words, it is not a mammalian-type sternum, which is what I ment by saying that sauropods don't have sternums. I ment "sternum" as a bone that connects ventrally with several pairs of ribs. If anything, sauropod sternums function more like clavicles.
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